A spinning line for producing a plurality of endless synthetic filament yarns.
To produce endless synthetic filament yarns spinning lines are used, wherein in a spinning apparatus the yarns are first spun from a molten plastic. To this end, a melt is supplied at a spinning position to a spinneret. The spinneret has a plurality of bores through which the molten plastic is extruded. The filaments individually emerging from the spinneret advance through a cooling zone and are combined to a yarn at the end of the cooling zone. In the spinning apparatus of a spinning line, a plurality of spinning positions are arranged side by side, so that six, eight, or maximally ten yarns are spun at the same time.
After the yarns have advanced through a treatment zone downstream of the spinning apparatus, they are wound to packages in a takeup apparatus. In the treatment zone, an individual treatment that depends on the polymer type and yarn type, is performed on the yarn by lubricating, drawing, heating, relaxing, entangling, or a combination of these treatment methods.
In such complex lines, disturbances are never totally preventable in the yarn path. Such disturbances may be caused, for example, by yarn breaks or formation of laps, for example in a godet system. To eliminate disturbance, as well as to avoid rejects, it is necessary that the web of yarns of the spinning line be cut and taken into a suction device. To this end, so-called yarn collection devices are provided in the spinning line.
U.S. Pat. No. 5,324,358 discloses such a yarn collection device, wherein each individual yarn advances through a cutting device and a suction device. In the case of a disturbance, the cutting device is activated. The yarn ends are taken over by the suction device. This ensures that the spinning apparatus of the spinning line continues its operation uninterrupted. The known yarn collection device has the disadvantage that each individual yarn is taken into a separate suction device. Since an operator guides the web of yarns in a manual suction device when threading the yarns in a spinning line, it will be necessary that the operator first remove each individual yarn from the suction device. In addition, the known yarn collection device requires a considerable expenditure for apparatus with a correspondingly high susceptibility to disturbances.
It is therefore the object of the invention to further develop a spinning line of the initially described kind such that it facilitates both a fast collection of the yarns and a correspondingly fast threadup of the yarns in the spinning line.
In accordance with the invention, this object is accomplished in that the yarn collection device comprises a movable yarn guide with a yarn guide groove in the plane of the yarn advance, a cutting device, and a suction device, the cutting device and suction device being arranged on one side of the web of yarns. Before cutting the yarns, the yarn guide is located on the opposite side of the group of yarns, and for cutting the yarns, it can be moved in direction of the cutting device. The advantage of the invention lies in that it is possible to combine the web of yarns to a bundle regardless of the number of yarns, and to supply same to a suction device. This bundling of the yarn web permits direct rethreading, for example, in the takeup apparatus without any substantial delay, after eliminating the disturbance. To this end, it would be possible to use, for example, a suction device that is constructed as a hand gun. To bundle and cut the group of yarns, only one movable yarn guide used, which results in a particularly simple construction of the yarn collection device.
To facilitate the cutting of the yarns in a tensioned state, the yarn guide has two yarn guide grooves adjoining each other in one plane, in which the individual yarns are collected. By deflecting the yarns, it is possible to tension partial lengths of the yarns that extend between the two yarn guide grooves. With that, it is easy to cut the yarn.
The cutting device preferably is formed by a cutter whose blade extends between the legs of the yarn guide during the cutting of the yarns. This ensures a reliable cutting of the yarns without movable structural parts. To facilitate collection of the yarns during the movement of the yarn guide parallel to the plane of the yarn advance, the yarn guide groove is made V-shaped, so that yarns slide with certainty into the yarn guide groove.
According to a further, particularly advantageous embodiment, the yarn guide is connected to a carriage that is movable by means of a drive along a straight guideway parallel to the plane of the yarn advance. This permits an unimpeded yarn advance in the spinning line when the yarn collection device is not activated. The carriage is arranged for movement along the straight guideway on the side of the yarn web.
In a particularly advantageous embodiment of the spinning line, the drive of the yarn guide is realized by a pneumatically movable magnetic piston inside a tube. This magnetic piston is coupled by magnetic forces with a countermagnet of the carriage. The countermagnet is arranged for movement with the carriage on the circumference of the tube. By the movement of the magnetic piston in the interior of the tube, it is possible to displace the yarn guide without additional displacement mechanisms. In this instance, it is preferred to move the magnetic piston in the interior of the tube pneumatically.
In a further, especially preferred embodiment of the spinning line, the drive is connected to a control unit which receives signals from a sensor arrangement that monitors the yarn paths. Upon occurrence of a disturbance, it is thus possible to bundle the yarns without substantial time delay.
According to a further advantageous embodiment of the spinning line, the sensor arrangement comprises a yarn break sensor for each yarn.